ISO/IEC JTC1/SC29/WG11N1249
March 1996 / Firenze
Source: Leonardo Chiariglione - Convenor
Title: MPEG Press Release
Status: Approved
Florence Press Release
Highlights
At its 34th meeting in Florence (Italy), from 25-29 March 1996, hosted by the Italian National Standardisation body UNINFO, the MPEG working group issued a Call for Proposals, asking for technology that can be used in the combined coding of synthetic and natural audio and video material. The ability to combine efficient representations of natural and both 2 and 3 dimensional synthetic data is an important feature of the upcoming MPEG-4 standard.
The work in MPEG-4 is driven by the changing ways that audiovisual information is produced (computer-generated content becomes more relevant) and consumed (interactivity increases). Next to that, the appearance of more powerful and flexible systems necessitates the definition of MPEG-4 as an open and flexible standard..
The technical work on the MPEG-4 video and audio coding tools continued through further development of the so-called 'Verification Models'. Also the 'MSDL', the glue that binds these tools together, was further defined. (MSDL: "MPEG-4 System and Description Languages".)
The audio subgroup produced the Working Draft (WD 13818-7) of the MPEG-2 NBC (Non-Backwards Compatible) multichannel audio coding scheme. The NBC mode is seeking to provide an optimised combination of bitrate and quality for multichannel audio coding.
Background
The work in MPEG is carried out in several sub groups, that work on specific issues. Around 300 experts took part in the work of these subgroups. The next meeting will take place from 8 through 12 July in Tampere, Finland, hosted by Nokia. The MPEG working group decided to have an extra meeting in September, which will be hosted by Motorola, and take place in Chicago. Whereas MPEG usually meets three times a year, this will be the second extra meeting in 1996, making it a total of 5. The start, at the beginning of this year, of technical work on MPEG-4 makes these extra meetings necessary.
A detailed list of the results of the 34th meeting follows below. The list is loosely organized according to the several sub groups that MPEG knows.
Details
'Hybrid coding'
MPEG-4 will internationally solicit technology for standardizing the coding of hybrid data that combines important features of traditional Audio/Visual and 2D/3D graphical data based on natural and synthetic sources. A Call for Proposals on Media Models (a coded representation of these data types) was released, to ask for wide industry participation in submitting proposals. Target technologies in 'synthetic/natural hybrid coding' include compression of hybrid data like geometry and structure, real-time synchronization and control, integration of mixed media types and temporal modeling. It also includes special forms of audio coding such as spatial localization in 2D/3D aural environments.
Potential applications include virtual environment simulation, conferencing, browsing, training, education, entertainment, media production and distribution, and related forms of real-time/ interactive and broadcast media experiences.
Audio
The group wrote the first complete description of the Verification Model for MPEG-4 audio, incorporating most of the functionalities identified by responses to the initial enquiry for contributions.
The audio subgroup produced the Working Draft (WD 13818-7) of the MPEG-2 NBC (Non-Backwards Compatible) multichannel audio coding scheme. The NBC mode is seeking to provide an optimised combination of bitrate and quality for multichannel audio coding, to be added to the MPEG-2 standard. This work will also be part of the MPEG-4 standard.
The critical listening tests conducted within the RACE dTTb project reported high quality results with MPEG-2 multichannel audio Layer II and Layer III codecs. Tests were done for both the multichannel and the stereophonic performance, with subjects evaluating codecs in single and cascaded modes, at bit rates from 512 kb/s to 896 kb/s.
Video
The MPEG-4 video Verification Model (VM) was further developed into version 2.0. The VM is a common model that experts use to carry out experiments 'at home', with the aim to further improve the coding tools.
The MPEG community welcomes the offer of two parties to make publicly available a software implementation of the VM. This will help many members of MPEG in carrying out experiments and therefore speed up the development of the standard.
An important issue in the video work for MPEG-4 is coding the visual material while taking account the actual objects in the scene. Work is also done on error resilience and the ability to cope with different media and bitrates ('scalable coding'). Coding efficiency has always been an issue in MPEG, and this is still the case for MPEG-4.
The Multiview Profile was promoted to Draft Amendment (DAM) status. The Multiview Profile is intended for applications that use stereoscopic vision. It can also be used for generating and displaying views from 'virtual cameras', by using images from multiple real cameras and interpolating between them. Detailed plans have been drafted to carry out subjective testing to evaluate the quality of MPEG's Multiview profile.
Already in the January meeting, the '4:2:2 Profile at Main Level' became a new MPEG standard for high quality video standard applications. This is the culmination of the work that started in November 1994. The 4:2:2 profile at Main Level permits better colour resolution, allows coding of all active video lines and can operate at a bitrate up to 50 Mbits per second.
This allows flexibility in choosing video quality and latency that are specific to the needs of studio applications, such as multiple generation coding (repeated encoding and decoding), digital effects and digital distribution.
Conformance
Part 4 of MPEG-2, which deals with Conformance testing, was promoted to the status of 'International Standard'. Conformanc testing is carried out to make sure that coders and decoders operate according to what is specified in the standard.
DSM-CC
The focus of the work on the Digital Storage Media - Command
and Control (DSM-CC) now concentrates on testing and validation
of the much anticipated standard. The use of DSM-CC is specified
by many network providers around the world, and DSM-CC has been
adopted by many fora working on standardization, such as the
Digital Audiovisual Council (DAVIC).
| Dr. Leonardo Chiariglione | |
+39 11 228 6129/6116/5111 |
| Multimedia and Video Services | |
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